The present invention relates to a liquid treatment system and more particularly to point-of-use water treatment systems.
Liquid treatment systems are commonly used to treat liquid in a distribution system. Such treatment systems typically remove contaminants from or alter contaminates in liquid to reduce consumption and use problems or enhance the aesthetic quality of the liquid.
A specific type of liquid treatment system is a water treatment system, which commonly is used in a water distribution system. A water treatment system removes pathogens, chemical contaminates, and turbidity from water that is used for human consumption. Water treatment systems may employ filtration components, ion exchange components, ultraviolet radiation components and the like to treat water as it flows through the water treatment system from a water supply to a point of distribution, for example, a faucet in a building.
Conventional water treatment systems connect a municipal or private pressurized water supply to a water distribution system. For example, an under-counter water treatment system, of the type used in residences or businesses, provides fluid communication between a pressurized water supply line and a faucet. As the water flows through the system, the system treats the water before it exits the faucet.
Although conventional water treatment systems provide a way to remove unwanted chemicals, pathogens and other contaminants from water, they suffer several shortcomings. First, water treatment systems typically are connected to a high pressure (e.g. 50 to 90 pounds per square inch) water supply. Under such high pressure, the systems occasionally fail as a result of a manufacturing defect, a design defect, end-user abuse or a pressure surge in the water supply. If severe enough, a pressure surge may rupture the water treatment system components, and result in an uncontrolled release of water from the system. Such a release has the potential to cause significant flood damage to the building or structure in which the water treatment system is located.
Some water treatment systems, for example, the system in U.S. Pat. No. 5,536,395 to Kuennen, include electric current interrupters that automatically disconnect the water treatment system from an electric source when water starts to leak onto electronic components in the system. Although this approach prevents electrocution of bystanders and damage to the electric supply, the system remains under pressure and thus still may cause water damage.
A second problem associated with conventional water treatment systems is that most include consumable components, for example, filters, ultraviolet bulbs and ion exchange chemicals that require occasional maintenance or replacement. This requires that the water supply be disconnected from the water treatment system to avoid spillage of water when the component is removed. This makes maintenance of the water treatment system time consuming and, in some cases, complex. Kuennen offers a solution to this problem as well by outfitting a filter with a system of check valves that automatically close once the filter is removed for maintenance. Accordingly, the water supply is shut-off and theoretically does not leak from the water treatment system. In some instances, however, if the check valves are abused by end-users, it is possible that water may leak from the check valves because the system remains under pressure. Moreover, if the filter cartridge of Kuennen is forcibly and improperly replaced, the check valves may remain stuck open, causing a slow leakage problem.
A third problem common to conventional water treatment systems is that if the plumbing downstream of the water treatment system bursts or ruptures, for example, due to freezing, the water treatment system allows water to flow freely to the burst or leaking region.